Roasted Turbotin with sauce beurre blanc Nantais

Beurre blanc is a light creamy sauce from the Loire Valley made almost entirely from butter. Beurre blanc Nantais is exactly the same sauce with the addition of a few tablespoons of cream.

The story goes that around the beginning of the 20th century, Clémence Lefeuve created the sauce by accident at her restaurant “La Buvette de la Marine” on the banks of the River Loire near the beautiful city of Nantes. Not having the egg yolks to make a Bearnaise or Hollandaise sauce, she whipped up a simple emulsion of white wine, lemon, shallots and butter and a new French classic was born.

Whatever the story, a beurre blanc sauce is easy to make; there is not much more technique than whisking! But it is a difficult sauce to hold and quickly breaks if overheated. Over time, chefs found that adding a couple tablespoons of heavy cream or crème fraiche made the sauce more stable.  This enriched version, beurre blanc Nantais, can be made a couple of hours in advance and will happily keep on the back of a stove, plate warmer, or in a mildly heated oven until needed.

Both beurre blanc and beurre blanc Nantais are rich and decadent. And both pair exceedingly well with not only fish, but seafood and vegetables as well.

Both sauces start by simmering shallots in a mixture of white wine and vinegar until there’s only 1 or 2 tablespoons of liquid left, barely enough to cover the shallots. Cold butter is then whisked into the reduction – with or without cream.

The sauce can be seasoned quite simply with just salt and white pepper. White pepper gives it a nice aromatic flavor without the dark speckles of black pepper. If the sauce tastes a little flat, stir in a dash of vinegar. If it tastes too sharp, add a few extra cubes of butter.  Finally, the sauce can be strained to remove the shallots. You can also leave them in for a little added texture.

Like most classic French sauces, beurre blanc adapts to dozens of variations. Feel free to get creative. Try adding ginger or garlic to the reduction or stirring in citrus juice or aromatic herbs such as basil, chervil or chives.

Any leftover beurre blanc can be spread onto grilled meat or vegetables like a compound butter. It can also be reheated and cooked to make a shallot flavored clarified butter, delicious for cooking seafood or meats.

A Turbotin is a young, flat, scaleless fish with an almost circular shape weighing under 2 kilos. Larger fish (anything over 2 kilos) are called turbo.

Like other flat fish that sit on the bottom of the seabed, buried in the sand, the turbot adapts the color of its skin to the environment. Their top sides can be light yellow, gray brown or almost black, but all are dotted with dark spots to reproduce the gravel or seashells on which they rest. The underside of the Turbot, the part snug against the sand, is always creamy white without pigmentation. Tubotin/Turbot is renowned for the delicacy of its flesh, so much so that it has earned the nickname “Prince of the Seas.”

Recipe for Roasted Turbotin with sauce beurre blanc Nantaise
Serves 2 to 4 depending on appetites

Sauce beurre blanc Nantaise:
Makes about 1 ½ cups

  • 2 tablespoons finely chopped shallots
  • ¼ cup good-quality white wine vinegar
  • ¼ cup dry white wine (traditionally a Muscadet, a crisp and acidic wine from the Loire Valley, but any dry white wine will do.)
  • 2 tablespoons heavy cream or crème fraiche
  • 2 sticks (1/2 lb) cold unsalted butter, cut into 1-inch cubes
  • Salt and white pepper to taste

Combine the wine, vinegar and shallots in saucepan over medium heat. It’s important that the size of the saucepan is at least as large as the heat source. If the source of heat is too large, the insides of the pan will brown and discolor the sauce. If you find this is the case, wipe the sides down with a clean, damp cloth or paper towel.

Simmer until only 1 or 2 tablespoons of liquid is left, barely enough to cover the shallots.

Add the cream and return to a simmer.

Over medium heat, begin adding the butter, whisking constantly until all the butter is incorporated. If at any point it looks oily or waxy, add 1 or 2 tablespoons of cream or water to cool it down and keep the sauce from breaking. As soon as the butter is incorporated into the sauce, remove the saucepan from heat. Season with salt and pepper, adjusting with more vinegar or butter according to taste. Keep warm until ready to use.

To cook the fish:

This recipe works for all varieties of white fleshed flatfish: halibut, flounder, sole or even seabass or bream. A whole fish cooked on the bone will have the best flavor, but filets can be cooked this way as well, just reduce the cooking time.

  • 2 whole Turbotin, gutted and gills removed, but skin on, weighting about 2 ¼ lbs each (it’s best to remove the gills, they can give the fish a bitter flavor)
  • 1 to 2 tablespoons of butter, cut into small pieces (plus more for the pan)
  • Olive oil
  • Salt and pepper
  • ½ cup dry white wine
  • 1 lemon, cut in half
  • Herbes de Provence (or other aromatic fresh herbs)

Preheat the oven to 425°F.

Rub a rim roasting pan large enough to accommodate the fish with butter (or olive oil). Lightly sprinkle the surface of the pan with salt and pepper.

Wash the fish and pat dry with paper towel. If you are cooking a large fish, make a few slashes through the thickest parts of the fish. This will allow the fish to cook faster and more evenly. Place fish on the prepared pan, pale side down.

Trickle olive oil over the fish, sprinkle generously with Herbes de Provence, salt and pepper and dot with the small pieces of butter. Pour the wine over and around the fish and give it all a good squeeze of lemon juice.

Bake for 20 to 30 minutes, or until the fish is just cooked.

Once roasted, the flesh should lift easily from the bone in neat fillets. Remove the top two fillets using a fish knife and fork, then ease the skeleton away to reveal the remaining two fillets from the underside.

Serve the fish with beurre blanc drizzled over the top.

Charlotte Puckette is a Grand Diplôme graduate of Paris’s Le Cordon Bleu, co-author of The Ethnic Paris Cookbook, as well as a private chef, caterer, cooking instructor, food consultant, and hostess.